This invention pertains to a catalytic hydroconversion process for heavy hydrocarbon liquid feedstocks to produce lower boiling hydrocarbon liquid and gas products. It pertains particularly to such a hydroconversion process in which supercritical solvent vapor extraction is used in-situ to dissolve the reactor liquid fraction and remove Ramsbottom carbon residue (RCR) and metals containing compounds to avoid their precipitation in downstream processing equipment and achieve high conversion.
In hydroconversion processes such as for petroleum residua feeds for producing lower boiling liquid products, it is usually necessary to remove a substantial portion of RCR-containing and metals-containing compounds from the liquid products to insure sustained operations. The solvent extraction of hydrocarbon materials using supercritical vapor is generally known. For example, the extraction of coal solids material using supercritical vapor solvents is disclosed in U.S. Pat. No. 3,558,468 to Wise, but does not disclose use of supercritical vapor extraction of a catalytically hydroconverted liquid fraction incorporated into a hydroconversion process. Also, the extraction of petroleum residua feedstocks using supercritical vapor extraction procedure before hydroconversion is disclosed in U.S. Pat. No. 4,354,922 to Derbyshire et al and U.S. Pat. No. 4,354,928 to Audeh et al. However, the present invention utilizes in-situ supercritical solvent vapor extraction following catalytic hydroconversion reaction to avoid the undesired precipitation of asphaltenes and provide sustained high hydroconversion operations on heavy hydrocarbon liquid feedstocks, particularly those containing high Ramsbottom carbon residue (RCR) materials and high metals containing compounds.